The symptoms that ruin my life (Urgent help)

Hello, I am writing this message to try to ask for urgent help.

I'm experiencing very, very unpleasant symptoms, I'm going to tell you about some of them:
I have been experiencing very severe pain in my muscles for over 5 years, I have undergone all the possible medical tests including MRI and various photographs, I have not found any physical problem. I feel that all the muscles in my body are very tight and tense, I can be seen outside with great muscle stiffness, I also experience very strong joint pain, weakness and fatigue. My doctor says he thinks the pain comes from a mental source.
I do not fall asleep at night, and every night I fall asleep after 6-8 hours of lying in bed when the sun rises, and I collapse with fatigue.

In addition to these pains, I experience symptoms of: jaw lock, teeth grinding during the day that does not stop, inability to stop moving the body, motor restlessness that is expressed in my feet always knocking on the ground My hands do something and move, I bite the skin in my cheeks inside Mouth and tearing it with teeth, and I scratch the flesh of the gums with my back teeth to the point of pain. I can not stop at any point in the day to stop these symptoms, I always feel very tense, as if every little noise and every little thing provokes a reaction of contraction and reflex all over my body.

I am only 18 years old, and my dentist claims that the wear on my teeth is like the creaking of an 80-year-old man who has gritted his teeth all my life and that I've ruined my teeth from grinding.

My eye muscles are always taken, I feel my eyes are really occupied, sometimes I experience fractures and strong body tremors, especially in the area of ​​my legs.
Sometimes my condition starts to tremble, I start to gnash my teeth, all my muscles begin to contract and I feel the need to scream, but all that happens is that my tears come out and my whole body contracts with fear.

The reason I write it now is that I could not fall asleep after 8 hours lying in bed and gritting my teeth and turning from side to side and biting the skin in my mouth.

The curious thing about all this is that I do not directly or openly experience pressure or anxiety, but perhaps repressed. I experienced a very, very difficult and different life, which included very strong childhood traumas, very long periods in which I wanted very much to commit suicide and to hurt myself. And periods of years in which I was imprisoned in isolation and suffered from total isolation and I have not seen any human being for more than three years.

Afterward, I moved into an apartment on my own and started to get to know people. My life feels better, but the symptoms of anxiety and pain still haunt me. I think I may have suppressed all the hard feelings, and I did not really care for them by trying to forget my previous life.

I feel that something in my subconscious controls me and makes me always feel unconsciously occupied and unconscious, so that the symptoms of stress are expressed only through the body and not through the mind.

I want to understand more about what is happening to me, and why do I suffer from so many symptoms related to anxiety and stress at once? What can I do to get rid of them?

I went to the psychiatrist and got anti-anxiety pills, he said they would help reduce the symptoms but they did not help me at all. Even when I took a little more than he recommended me to take.

I mainly want to understand what is happening to me, and to learn more about the symptoms I suffer from. I want to understand more about what stress is actually, and how does it affect the body in all forms?

I would appreciate your detailed response, thank you.